A comprehensive update on current fixation options for two-part proximal humerus fractures: a biomechanical investigation

Richard S Yoon; Daniel Dziadosz; David A Porter; Matthew A Frank; Wade R Smith; Frank A Liporace

doi:10.1016/j.injury.2013.08.024

A comprehensive update on current fixation options for two-part proximal humerus fractures: a biomechanical investigation

Injury. 2014 Mar;45(3):510-4. doi: 10.1016/j.injury.2013.08.024. Epub 2013 Sep 7.

Authors

Richard S Yoon¹, Daniel Dziadosz², David A Porter², Matthew A Frank², Wade R Smith³, Frank A Liporace⁴

Affiliations

¹ Division of Orthopaedic Trauma, Department of Orthopaedic Surgery, NYU Hospital for Joint Diseases, New York, NY 10003, USA.
² Division of Orthopaedic Trauma, Department of Orthopaedic Surgery, INOVA Fairfax Hospital, Faiefax, VA 22003, USA.
³ Division of Orthopaedic Trauma, Department of Orthopaedic Surgery, Swedish Medical Center, Denver, CO 80204, USA.
⁴ Division of Orthopaedic Trauma, Department of Orthopaedic Surgery, NYU Hospital for Joint Diseases, New York, NY 10003, USA. Electronic address: liporace33@gmail.com.

PMID: 24168862
DOI: 10.1016/j.injury.2013.08.024

Abstract

Background: Recent advancements in implant technology offer updated options for surgical management that have been rapidly adopted into clinical practice. The objective of this study is to biomechanically test and compare the current fixation options available for surgical fixation of two-part proximal humerus fractures and establish load to failure and stiffness values.

Methods: Sixteen match-paired (32 total) fresh-frozen, cadaveric specimens were randomized to receive 1 of 4 fixation constructs following creation of an AO/OTA Type 11A3 (two-part) proximal humerus fractures. Fixation constructs tested consisted of 3.5 mm fixed angle plate (3.5-FAP), 4.5 mm fixed angle plate (4.5-FAP), humeral intramedullary nail (IMN), and a humeral intramedullary nail with a fixed angle blade (IMN-FAB). Specimen bone density was measured to ensure no adequate, non-osteoporotic bone. Constructs were tested for stiffness and ultimate load to failure and compared via one-way ANOVA analysis with subsequent post hoc Tukey HSD multiple group comparison statistical analysis.

Results: The IMN-FAB construct was significantly stiffer than the 3.5-FAP construct (123.8 vs. 23.9, p<0.0001), the 4.5-FAP construct (123.8 vs. 33.3, p<0.0001) and the IMN construct (123.8 vs. 60.1, p=0.005). The IMN-FAB construct reported a significantly higher load to failure than the 3.5-FAB construct (4667.3 N vs. 1756.9 N, p<0.0001), and the 4.5-FAP construct (4667.3 N vs. 2829.4 N, p=0.019, Table 2). The IMN construct had a significantly higher load to failure than the 3.5-FAP construct (3946.8 vs. 1756.9, p=0.001, Table 2).

Conclusion: Biomechanical testing of modern fixation options for two-part proximal humerus fracture exhibited that the stiffest and highest load to failure construct was the IMN-FAB followed by the IMN, 3.5-FAP and then the 4.5-FAP constructs. However, prospective clinical trials with longer-term follow-up are required for definitive assessment of the ideal fixation construct for surgical management of two-part proximal humerus fractures.

Keywords: Fixed angle blade; Fixed angle plate; Intramedullary nail; Locked plate; Proximal humerus fracture.

Publication types

Comparative Study
Evaluation Study

MeSH terms

Biomechanical Phenomena
Bone Density
Bone Nails*
Bone Plates*
Cadaver*
Female
Fracture Fixation, Intramedullary* / methods
Humans
Humeral Fractures / pathology
Humeral Fractures / surgery*
Male
Random Allocation
Weight-Bearing